Methods and devices for evanescently coupling light having different wavelengths to an open dielectric resonator

Abstract

One feature pertains to an apparatus that includes apparatus that includes an evanescent field coupler having a first surface that evanescently couples light between the evanescent field coupler and an open dielectric resonator. The apparatus also includes a thin film coating covering at least a portion of the first surface of the evanescent field coupler. The thin film coating is specifically designed so that the thin film coating reflects light of a first wavelength.

Description

CLAIM OF PRIORITY[0001]The present application for patent claims priority to provisional application No. 62 / 519,029 entitled “Scheme for Efficient Coupling of Light with Different Wavelength to the Same Open Resonator” filed Jun. 13, 2017, the entire disclosure of which is hereby expressly incorporated by reference.FIELD[0002]Various aspects of the present disclosure relate to photonics and, more particularly, to methods and apparatuses for equalized evanescent coupling of light having different wavelengths to an open dielectric resonator.INTRODUCTION[0003]Many opto-electronic devices utilize evanescent field couplers to evanescently couple light into and out of optical resonators including whispering gallery mode resonators (WGMR). For example, an opto-electronic device may include a coherent light source, an evanescent field coupler, and a WGMR. The light source may generate predominately two different wavelengths of light that pass through the coupler and evanescently couple into...

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Benefits of technology

[0007]According to one aspect, the plurality of layers include a first set of layers composed of a first material and a second set of layers composed of a second material, the first set of layers interleaved with the second set of layers to form an alternating layer structure. According to another aspect, the first material and the second material have different indexes of refraction, and the refractive index of the first material, the refractive index of the second material, and a selected thickness of each layer of the plurality of layers cause constructive interference of light of the first wavelength at the thin film coating to increase reflection of light of the first wavelength when light of the first wavelength is incident upon the first surface of the coupler and / or a surface of the open dielectric resonator at a grazing angle less than 0.1 radians. According to yet another aspect, the plurality of layers each have at least one of a different thickness and / or a different index of refraction.

[0008]According to one aspect, the thin film coating is configured to increase reflection of light of the first wavelength when light of the first wavelength is incident upon the first surface of the coupler and / or a surface of the open dielectric resonator at a grazing angle less than 0.1 radians. According to another aspect, the thin film coating operates as a wavelength selective dielectric mirror that reflects more than 90% of the power of the light of the first wavelength. According to yet another aspect, the thin film coating is further configured to decrease the coupling efficiency of light of the first wavelength and boost loaded quality factor Q of light of the first wavelength propagating within the open dielectric resonator. According to another aspect, the evanescent field coupler is a prism or a waveguide.

Problems solved by technology

Selecting the distance d between the coupler and WGMR to maximize coupling of light at a first wavelength may not efficiently couple light at a significantly different second wavelength.

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